Rear bumper for an automobile



FIG. 1 is a front perspective view of a rear bumper for an automobile of my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom view thereof.

The rear view thereof is not visible during ordinary use and forms no part of the claimed design. 

The ornamental design for a rear bumper for an automobile, showing my new design. 